1. Field
This application relates to hand tools used for applying rotary motion to objects, specifically to an improved manually operated, dual grip, dual end design that allows the rotational speed, direction, and torque to be ergonomically and easily applied, varied, and controlled.
2. Prior Art
Applying rotary motion to objects such as screws, bolts, sockets, hex bits, drill bits, shafts, generators, drives, etc. has been done via a multitude of manually operated and powered hand tools. Most have drawbacks such as too slow, too fast, inadequate torque, heavy, fatigues user quickly, needs a power cord or power source. A simple straight screw driver is slow, may require a very firm grip, fatigues the hand and arm quickly, and requires repeated stopping and regripping. A ratcheting screw driver requires repeated stopping and reversing and also fatigues the hand and arm quickly. A Yankee-Style (spiral drive) screw driver turns when the handle is on the push stroke but then requires a pull stroke, opposite the bit engaging force, during which it does not turn. To change rotation direction requires stopping and moving a switch. It can be hard to hold this screw driver aligned and engaged with a screw. A ratchet screw driver or wrench requires repeated stopping and reversing. Reversing a ratchet screw driver or ratchet wrench requires stopping and turning a sleeve or flipping a lever. A pneumatic driver requires connection to a compressed air supply via a hose that must be long enough to reach the work. The hose can get tangled or caught on things. The weight and drag of the hose must be counteracted when using the pneumatic driver.
A corded electric driver may be heavy, requires connection to a power source via an electrical cord long enough to reach the work. The cord may get tangled or caught on things. The weight and drag of the cord must be counteracted when using the electric driver. Electric drivers should not be used in wet environments due to the potential for electric shock and cannot be used underwater unless of special sealed design. Electric drivers can be noisy and objectionable in areas or situations requiring quiet, such as a library, workplace, hospital or stealth military operation. A battery powered drill can be heavy, lack torque, and must be periodically recharged at a power source. If the battery does not have a charge or loses charge then it can't be used until it is charged, which may take a long time. An electric driver, even if variable speed and high torque, can be hard to control, especially when trying to apply sufficient torque to fully seat a screw then immediately stop rotation when fully seated. A variable speed electric drill with screw driver bit must be run at or near full power to get enough torque to drive the screw in fully. This makes it hard to stop the drill when the screw is fully seated. If not stopped at the correct time/position it may over tighten and damage the material receiving the screw, deform and damage the fastener drive, deform and damage the drive bit tip or break off the head of the fastener. Reversing an electric drill requires flipping a switch.
U.S. Pat. No. 7,197,965 Pivoted Socket Wrench Speed Handle teaches a jointed handle which allows the joints to be locked at angular positions. This does not allow fluid adjustments of speed and torque, such as is desired when screwing a sizeable screw into wood. It can be hard to hold in alignment with and engaged with the object being rotated.
U.S. Pat. No. 4,334,445 Z Style Speed Wrench teaches a jointed tool with a rotating handle. It can be hard to hold in alignment with and engaged with the object being rotated. The tool will easily slip off the object to be rotated if not held against it. This is especially true when the Z configuration is elongated for speed, the tool will tend to slip off the object being rotated. At high speed the centrifugal force of the connecting section tends to pull the coupled end sideways and off the object to be rotated. Fasteners such as a Phillips head screw require an axial engagement force proportional to the torque being applied in order to keep the Phillips bit and screw head engaged, otherwise either may deform and be damaged (“cam out”), which can result in either being made unusable. It does not provide for using both ends of the tool to rotate objects.
U.S. Pat. No. 2,712,765 Wrist-Motion Rotary Hand-Tool teaches the wrist motion but lacks any way to vary the handle position to vary speed and torque. It can be hard to hold in alignment with and engaged with the object being rotated. It is not able to develop much torque.
U.S. Pat. No. 7,299,718 Multi-Folding Screwdriver teaches a folding screw driver with torque limiter. It can be hard to hold in alignment with and engaged with the object being rotated. It does not provide for using both ends of the tool to rotate objects. It does not allow for good control over the amount of torque applied to the object to be rotated.
U.S. Pat. No. 5,349,886 Hand Screw Driver teaches a wrist motion screw driver with two positions. It can be hard to hold in alignment with and engaged with the object being rotated. It does not provide for using both ends of the tool to rotate objects.
It is, therefore, a primary objective of this application to provide a tool than can be used to apply rotary motion to an object via human power that is ergonomic to use and allows the applied rotational speed, torque, direction, and axial force to be easily varied and controlled. It is a further object of this invention to provide a tool that can be used to create substantial amounts of torque but also operate at moderately high speed. It is a further object of this application to provide a tool that can be compactly folded and is light weight. It is also an object of this application to provide a tool that is quiet, can be used in wet environments, is reliable, and always ready for use (needs no power source). It is also an object of this application to provide a tool that can be used to rotate many different objects, adapters, and drives. It is a further object of this application to provide a tool whose construction can be varied to suit the needs of a multitude of applications.
This application provides two handles. One handle is used as a steadying handle for keeping the tool axially aligned with the object to be rotated and to apply axial force to maintain engagement with the object to be rotated. The other handle is swiveled, cranked or levered about the first handle to create rotary motion and torque. Both handles are functionally equivalent so that either end of the tool can be used for either steadying or cranking. The design can be made such that the handle used for cranking can also apply axial force to maintain engagement with the object to be rotated or for the purpose of drilling.
This tool is much easier to use, more ergonomic, than a traditional screwdriver because the required grip for a given torque is reduced. This application produces much less operator fatigue than a traditional screwdriver. It is much faster than a traditional screw driver or ratchet drive, as the motion is continuous in the desire direction. No repetitive re-gripping, as with a screwdriver, and no repetitive reversing direction, as with a ratchet. The rotation direction is easily and quickly reversible without requiring stopping and flipping a switch or ratchet pall.
This application is relatively light weight, much lighter than a corded electric drill or battery powered drill. It can be used safely in a wet environment, used submerged under water or even in outer space. This application is more reliable because it has no gears or brushes to wear out, no electrical windings to fail, nor cord to fray or come unplugged. This application works quietly whereas a drill motor can be noisy which is objectionable in some quiet situations such as a hospital, library, office or stealth military operation. This application is human powered so it never needs a power source or recharging, it is always ready to be used. This is an environmentally friendly “green” tool in that it is powered by a human that runs on a renewable energy resource, food. No batteries will ever be discarded as a result of using this tool.
This application can easily and fluidly be repositioned to vary the rotational speed, torque, and force applied. It can be made in a multitude of sizes, member lengths, and configurations to accommodate small delicate fastener requiring less torque and perhaps more speed, large fasteners requiring more torque and perhaps less speed, small drill bits requiring more speed or large drill bits requiring more torque. It can be made so that it provides a substantial amount of torque. For example it can be used to fully screw in a ⅜″ diameter×4″ long lag bolt (large hexagon head screw) into pine wood without the use of a pilot hole. It provides for good control of the applied speed, torque, and or axial force so that fasteners can be tightened fully as desired but not over tightened, thus preventing damage to fastener, bit and or work piece. This application can be made to fold compactly for storage in a small tool box or for carrying in a pocket or holster. It can also be made so that when folded it can be used like a conventional screwdriver.
The driver ends can be a single drive type such as Phillips or hexagon key or made such that it will accept interchangeable existing hex bits, sockets, and drill bits (via an attached drill chuck or drill bits with hexagon ends). The tool can be turned end for end as both ends are usable and can have integral driving bits or adapters affixed to both ends at the same time, allowing it to be used to rotate two types or sizes of objects without changing adapters. For example, two sockets of different sizes could be affixed to square drive ends. The tool ends could be the same size, such as ¼″ square drive, or different, say one ¼″ square drive and the other ⅜″ square drive. It could have a hex bit adapter on both ends with a wood screw driving hex bit in one end and a corresponding hex bit pilot drill affixed in the other end. One end could be a drill chuck for holding drill bits or hex bits. A Phillips bit on one and a flat screw driver bit on the other end. Thus two ends or affixed adapters are ready for use. The driver ends can also have rotatable indexable hubs with a plurality of drive tips on each hub, thus greatly increasing the number of drive tips that are available for use.
The tool's pivot joints are not fixed at various positions. This allows them to be easily and fluidly repositioned to vary the rotational speed and torque during use. A pivot rotation limiting stop can be incorporated on one or both pivots so that the members swing through a predetermined pivot angle and then stop. This allows axial force from the crank handle to be transmitted through the connecting member, to the output member and its end or adapter to provide additional axial engagement force with the object being rotated or for drilling.
When drilling it is important to hold the bit in the same position to start and in axial alignment while the hole is being drilled. Steadying via the output member's handle greatly assists in maintaining the position and axial alignment. To further minimize axial misalignment, an extension of sufficient length can be used between the drill and the output member. This reduces the angle of misalignment for a given amount of sideways movement of the steady handle. An adapter with a slightly swiveling joint can also be used to limit the effect of misalignment when drilling. Once the hole is started, the swivel joint allows the tool to be slightly out of alignment with the drill bit, without putting stress on the drill bit, which is aligned with the axis of the hole it is making.
The tool is very ergonomic to use, versatile in its ability, range of use and characteristics. It has two comfortable handles for ease of use. It can be made to use a multitude of adapters, drives and drill chucks. It can be used as a swivel, crank, or lever, be used as a conventional screwdriver or conventional tee handle driver. It can produce a good amount of rotational speed and substantial amounts of torque. It can be used with small screw fasteners, nuts and bolts, machine drives, pumps and drills. It needs no power source, is quiet, can be made small and lightweight or large and heavy duty, and made to fold compactly. This is a very useful tool.